Novel biosensor fabrication methodology based on processable conducting polyaniline nanoparticles

This work investigates polyaniline (PANI) nanoparticles, (synthesised using dodecylbenzenesulphonic acid (DBSA) as a dopant), as a novel, highly processable, non-diffusional mediating species in an enzyme biosensing application. These nanoparticles are readily dispersed in aqueous media which helps overcome some of the processability issues traditionally associated with polyaniline. Modification of screen-printed electrodes was readily achieved with these aqueous nanoparticle dispersions, where the nanoparticles were simply cast by a drop-coating method onto the surface. After suitable pH adjustment, it was shown that horseradish peroxidase (HRP) enzyme could be added to the dispersion, and cast simultaneously with the conducting polyaniline. This effective fabrication method involves no electrochemical steps, and as such is easily amenable to mass production. The feasibility of casting enzyme with polyaniline nanoparticles is demonstrated in this short communication. More accurate deposition of protein-containing inks onto screen-printed carbon working electrodes could in the future transfer the drop-coating protocol from manual deposition to largescale production by mechanical methods such as ink-jet printing

Wet-Spun Trojan Horse Cell Constructs for Engineering Muscle

Engineering of 3D regenerative skeletal muscle tissue constructs (skMTCs) using hydrogels containing muscle precursor cells (MPCs) is of potential benefit for repairing Volumetric Muscle Loss (VML) arising from trauma (e.g., road/industrial accident, war injury) or for restoration of functional muscle mass in disease (e.g., Muscular Dystrophy, muscle atrophy). Additive Biofabrication (AdBiofab) technologies make possible fabrication of 3D regenerative skMTCs that can be tailored to specific delivery requirements of VML or functional muscle restoration. Whilst 3D printing is useful for printing constructs of many tissue types, the necessity of a balanced compromise between cell type, required construct size and material/fabrication process cyto-compatibility can make the choice of 3D printing a secondary alternative to other biofabrication methods such as wet-spinning. Alternatively, wet-spinning is more amenable to formation of fibers rather than (small) layered 3D-Printed constructs. This study describes the fabrication of biosynthetic alginate fibers containing MPCs and their use for delivery of dystrophin-expressing cells to dystrophic muscle in the mdx mouse model of Duchenne Muscular Dystrophy (DMD) compared to poly(DL-lactic-co-glycolic acid) copolymer (PLA:PLGA) topically-seeded with myoblasts. In addition, this study introduces a novel method by which to create 3D layered wet-spun alginate skMTCs for bulk mass delivery of MPCs to VML lesions. As such, this work introduces the concept of “Trojan Horse” Fiber MTCs (TH-fMTCs) and 3d Mesh-MTCs (TH-mMTCs) for delivery of regenerative MPCs to diseased and damaged muscle, respectively

Antiepileptic effects of lacosamide loaded polymers implanted subdurally in GAERS

The current experiment investigated the ability of coaxial electrospun poly(D,L-lactide-co-glycolide) (PLGA) biodegradable polymer implants loaded with the antiepileptic drugs (AED) lacosamide to reduce seizures following implantation above the motor cortex in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS). In this prospective, randomized, masked experiments, GAERS underwent surgery for implantation of skull electrodes (n = 6), skull electrodes and blank polymers (n = 6), or skull electrodes and lacosamide loaded polymers (n = 6). Thirty-minute electroencephalogram (EEG) recordings were started at day 7 after surgery and continued for eight weeks. The number of SWDs and mean duration of one SWD were compared week-by-week between the three groups. There was no difference in the number of SWDs between any of the groups. However, the mean duration of one SWD was significantly lower in the lacosamide polymer group for up to 7 weeks when compared to the control group (0.004 \u3c p \u3c 0.038). The mean duration of one seizure was also lower at weeks 3, 5, 6, and 7 when compared to the blank polymer group (p = 0.016, 0.037, 0.025, and 0.025, resp.). We have demonstrated that AED loaded PLGA polymer sheets implanted on the surface of the cortex could affect seizure activity in GAERS for a sustained period

Reversible photochromic polynorbornenes bearing spiropyran side groups for layer-by-layer coatings

A great number of stimuli-responsive materials have been reported in the recent years and they find applicability in fields ranging from optoelectronics, surface coatings, photonics and biomedicine. A particular attractive class of stimuli-responsive materials is comprised by photo-responsive materials as light is an environment-friendly stimulus and can be applied remotely, in a non-invasive manner. Photo-responsive materials have been the subject of many investigations over the past decade due to their potential applications, particularly in the design and development of memory devices, artificial muscles, soft-actuators and drug delivery, among others[1]. In the field of photo-responsive polymers, the layer-by-layer (LbL) approach offers a simple and effective method to fabricate uniform thin films capable of photo-modulation. In this context, we are focusing our investigations on the synthesis of LbL coatings based on new photochromic norbornenes polymers bearing spiropyran side groups. We have shown that these LbL coatings are capable of disassembling upon photostimulation. When used for the coating of microcapsules, these polymers have the ability to be used for photo-controlled drug delivery. [1] L. Florea, D. Diamond, F. Benito-Lopez, Macromol. Mater. Eng. 2012, 297, 1148

In vitro growth and differentiation of primary myoblasts on thiophene based conducting polymers

Polythiophenes are attractive candidate polymers for use in synthetic cell scaffolds as they are amenable to modification of functional groups as a means by which to increase biocompatibility. In the current study we analysed the physical properties and response of primary myoblasts to three thiophene polymers synthesized from either a basic bithiophene monomer or from one of two different thiophene monomers with alkoxy functional groups. In addition, the effect of the dopants pTS- and ClO4 - was investigated. In general, it was found that pTS- doped polymers were significantly smoother and tended to be more hydrophilic than their ClO 4 - doped counterparts, demonstrating that the choice of dopant significantly affects the polythiophene physical properties. These properties had a significant effect on the response of primary myoblasts to the polymer surfaces; LDH activity measured from cells harvested at 24 and 48 h post-seeding revealed significant differences between numbers of cells attaching to the different thiophene polymers, whilst all of the polymers equally supported cell doubling over the 48 h period. Differences in morphology were also observed, with reduced cell spreading observed on polymers with alkoxy groups. In addition, significant differences were seen in the polymers\u27 ability to support myoblast fusion. In general pTS- doped polymers were better able to support fusion than their ClO4 - doped counterparts. These studies demonstrate that modification of thiophene polymers can be used to promote specific cellular response (e.g. proliferation over differentiation) without the use of biological agents. 2013 The Royal Society of Chemistry

An Integrated Framework for Intersectorality: Nonprofitness and Its Influence on Society and Public Administration Programs

Cross-sector interactions have long occurred in the public delivery of goods, services, and interests. While scholars have often addressed cross-sector interactions using the dimensions of publicness (state) and privateness (market), an intersectoral framework necessitates the understanding and incorporation of nonprofitness to account for the dimensions of nonprofits along the public-private continuum. This article proposes a framework for identifying the dimensions of nonprofits in an intersectoral world and draws on relevant examples to illustrate the presence and influence of nonprofitness. The article then focuses on the future of education in the field of public administration and, in light of the proposed framework, makes and considers recommendations to help educational programs better equip students to appreciate work across sectors

A theoretical model of inflammation- and mechanotransduction- driven asthmatic airway remodelling

Inflammation, airway hyper-responsiveness and airway remodelling are well-established hallmarks of asthma, but their inter-relationships remain elusive. In order to obtain a better understanding of their inter-dependence, we develop a mechanochemical morphoelastic model of the airway wall accounting for local volume changes in airway smooth muscle (ASM) and extracellular matrix in response to transient inflammatory or contractile agonist challenges. We use constrained mixture theory, together with a multiplicative decomposition of growth from the elastic deformation, to model the airway wall as a nonlinear fibre-reinforced elastic cylinder. Local contractile agonist drives ASM cell contraction, generating mechanical stresses in the tissue that drive further release of mitogenic mediators and contractile agonists via underlying mechanotransductive signalling pathways. Our model predictions are consistent with previously described inflammation-induced remodelling within an axisymmetric airway geometry. Additionally, our simulations reveal novel mechanotransductive feedback by which hyper-responsive airways exhibit increased remodelling, for example, via stress-induced release of pro-mitogenic and procontractile cytokines. Simulation results also reveal emergence of a persistent contractile tone observed in asthmatics, via either a pathological mechanotransductive feedback loop, a failure to clear agonists from the tissue, or a combination of both. Furthermore, we identify various parameter combinations that may contribute to the existence of different asthma phenotypes, and we illustrate a combination of factors which may predispose severe asthmatics to fatal bronchospasms